1. Field of the Invention
The present invention relates generally to signal measurement systems and, more particularly, to generating trigger definitions in a signal measurement system.
2. Related Art
Analyzers and testers are commonly available to assist in the development, manufacturing and troubleshooting of complex digital electronic/software devices and integrated circuits having incorporated therein microprocessors, random-access memories (RAM), read-only memories (ROM), and other circuits. Such analyzers and testers, generally referred to as signal measurement systems include logic analyzers, digital oscilloscopes, protocol analyzers, microprocessor emulators, bit error rate testers, network analyzers, among other instruments. Logic analyzers in particular have emerged for this purpose and are commercially available from a number of vendors, such as Hewlett-Packard Company, Tektronix, Inc., and others.
Logic analyzers are digital data acquisition instruments that allow an operator to acquire and display digital signal data from a large number of logic signals (xe2x80x9csignalsxe2x80x9d), such as those that travel over address, data and control lines of a device under test (DUT). A device under test may include one or more separately packaged devices such as those noted above as well as other circuits and devices.
The signals are acquired from the device under test on hardwired lines referred to as channels. The channels may be physically assembled into groups commonly referred to as pods. The received signals are sampled and digitized to form signal data. Digitizing typically includes comparing a voltage magnitude of each logic signal sample to a reference voltage to determine the logic state of the signal. Sampling may occur at one of a number of selectable rates, depending on the frequency at which the sampled signals change logic states. The resultant signal data are stored, under the control of a sampling clock, in a signal data memory generally having a fixed size. The data are typically stored in a sequential manner such that consecutive signal samples are stored in consecutive memory locations. Due to the quantity of signal data, signal data memory is commonly implemented as a wrap-around buffer.
Selection of the signal data to be subsequently presented on a display is determined by an operator-defined trigger specification. The trigger specification (also referred to as a trigger set-up) is specified generally by a trigger definition, and a number of parameters collectively referred to herein as trigger control parameters or, simply, trigger controls. The trigger definition identifies the occurrences that result in signal data being stored. The trigger controls identify the characteristics of the captured signal data including, for example, the relative position of the occurrence defined by the trigger definition and the signal data to be stored. A predetermined quantity of signal data occurring before and after the specified occurrence is then stored in memory for subsequent analysis.
A trigger definition, also referred to as a trigger sequence, is comprised of one or more trigger sequence levels. Each sequence level may include any number of trigger branches each of which sets forth a branch condition that causes the logic analyzer to execute the action defined in that trigger branch. Such execution results in the storage of signal data or further processing of a subsequent sequence level. The final branch condition that causes the acquisition of signal data is commonly referred to as a trigger condition.
Branch conditions are specified by the occurrence of one or more events. An event is defined as an occurrence of certain characteristics or properties of a signal, such as a rising or falling edge of a signal, a logic high or logic low signal state, etc. Events may also be defined based on internal resources, such internal timers, counters, etc. Typically, a branch condition specifies a number of events that occur simultaneously or in a relative time sequence.
After the trigger specification is specified, the operator can perform a measurement; that is, initiate acquisition of signal samples. When signal data capture is initiated, the signal data is compared to the specified trigger definition. When the trigger definition is satisfied, signal data is captured in accordance with the specified trigger controls and stored in signal data memory. Subsequently, the signal data memory may be sequentially accessed and signal data memory displayed.
Constructing a trigger definition can be very complicated and time consuming. Conventionally, trigger definitions are expressed in an esoteric trigger programming language. Learning such a programming language is often difficult; proficiency often requires many years of practice. However, even with such proficiency and knowledge, formulation of even simple trigger definitions still requires considerable time and effort due to the complexity of the programming language. In other words, such programming languages, although suited for development of complicated trigger definitions, are burdensome to developing simple and complicated trigger definitions alike.
The present invention is an integrated trigger function display system and methodology for trigger definition development in a signal measurement system having a graphical user interface. The present invention contemporaneously displays one or more trigger function names and an associated trigger function descriptor describing a trigger function identified by the associated trigger function name. The trigger name is displayed in a trigger name display region of a display window that concurrently displays a plurality of trigger function names. The descriptor is contemporaneously displayed in a trigger descriptor region of the display window so as to be visually-associated with the associated trigger name by the operator.
A trigger definition is comprised of one or more trigger functions. Each trigger function is a graphical representation of an underlying one or more trigger primitives. A trigger primitive is translated into a form suitable for controlling the signal measurement system. Trigger primitives comprise one or more trigger branches used to form a sequence level of the trigger definition. For a selected trigger function, either the trigger function or its underlying trigger primitives are displayed in a trigger definition region of the display window for editing by the operator. Preferably, multiple such trigger functions or primitives may be selected and displayed in a trigger definition region on the display window simultaneously or sequentially to form a desired trigger definition.
A number of aspects of the invention are summarized below, along with different embodiments of each of the summarized aspects. It should be understood that the embodiments are not necessarily inclusive or exclusive of each other and may be combined in any manner that is non-conflicting and otherwise possible, whether they be presented in association with a same or different aspect of the invention. It should also be understood that these summarized aspects of the invention are exemplary only and are considered to be non-limiting.
In one aspect of the invention, an integrated trigger function display system for trigger definition development in a signal measurement system having a graphical user interface is disclosed. The trigger function display system is constructed and arranged to contemporaneously display in a visually-associated manner a trigger function name and an associated trigger function descriptor. The trigger function name identifies an associated trigger function while the descriptor provides additional description of the trigger function identified by the associated trigger function name. The trigger name is displayed in a trigger name region of a display window that concurrently displays a plurality of trigger function names. The descriptor is displayed in a trigger descriptor region of display window. In one embodiment, a trigger definition region is contemporaneously displayed in the display window for editing by the operator. For a selected trigger function, either a trigger function display or one or more underlying trigger primitives comprising the selected trigger function is displayed.
In one embodiment, the integrated trigger function display system includes a trigger function resource library including a plurality of predefined trigger function objects. Each trigger function object includes a trigger function name, one or more trigger primitives, and a corresponding trigger function display for representing one or more trigger primitives on the graphical user interface, and a trigger function descriptor associated with the trigger function object. The library also includes a trigger definition maintenance module constructed and arranged to maintain copies of selected trigger function objects that form a current trigger definition and to convert the selected trigger functions to a trigger primitive form for subsequent translation to a form suitable for capturing signal data in the signal measurement system.
In another aspect of the invention, a trigger development system for trigger definition development in a signal measurement system having a graphical user interface is disclosed. The trigger function display system is constructed and arranged to contemporaneously display in an operatively integrated and visually-associated manner, a trigger name display region, an associated trigger function descriptor and a trigger definition region. A trigger function name is displayed in the trigger name display region. An associated trigger function descriptor describing a trigger function identified by the associated trigger function name is displayed in the descriptor display region. A trigger function is displayed in a trigger definition region of display window for editing, wherein a trigger function is generated in the trigger definition display window in response to an operator selection on the trigger function name display region or the trigger descriptor display region on graphical user interface.
In a still further aspect of the invention, a trigger display system for trigger definition development in a signal measurement system having a graphical user interface is disclosed. The trigger display system displays a trigger name region having names corresponding to electable trigger functions and a trigger definition region including a first trigger definition comprising a plurality of selected trigger functions displayed in corresponding sequence levels, one or more of multiple sequence levels designated to comprise a user-created trigger function wherein the operator-created trigger function is configured to be a selectable trigger function and wherein selection of user-created trigger function results in inclusion of one or more sequence levels in a second trigger definition.
In another aspect of the invention, a method for providing a trigger development environment in a signal measurement system that acquires signal data in accordance with a trigger definition is disclosed. The signal measurement system includes a graphical user interface and a data storage unit. The method includes a step of: a) displaying contemporaneously on the graphical user interface a trigger name region having a plurality of trigger function names displayed therein, each trigger name identifying an associated trigger function, and a trigger descriptor region operatively coupled to the trigger names display region and having a first trigger function descriptor displayed therein, wherein the trigger function descriptor is visually associated with an identified one of plurality of trigger function names displayed within trigger names display region.
In one embodiment, step a) further includes the step of: 1) displaying in trigger descriptor region a second trigger function descriptor visually associated with a second of plurality of trigger function names in response to a user identification of second trigger function name. In another embodiment, step b) includes the steps of: 1) receiving one or more availability factors, each availability factor providing information indicative of a current measurement scenario; 2) determining which the libraries contain trigger functions qualifying for a current measurement scenario; and 3) retrieving one or more trigger functions from qualifying trigger function libraries. In another embodiment, step d) includes the steps of: 1) receiving an operator selection of a described sequence level relative to which a desired trigger function is inserted; 2) select a desired trigger function from plurality of trigger functions displayed in trigger function name display region; and 3) incorporating selected trigger function in accordance with an operator insert instruction.
In another aspect of the invention, a method of creating a trigger function for use in a trigger development environment in a signal measurement system that acquires signal data in accordance with a trigger definition is disclosed. The method includes the steps of: a) creating a trigger definition having a plurality of trigger functions; b) receiving an operator selected two or more of the plurality of trigger functions; and c) including two or more trigger functions in a second trigger definition.
In a further aspect, a method of providing a trigger development environment in a signal measurement system is disclosed. The method includes the steps of: a) creating a display window having three regions; b) creating a list of trigger function names in a first of the three regions; c) creating a descriptor region having at least one descriptor visually-associated with a corresponding one of the list of trigger function names in a second of the three regions; and d) creating a trigger definition where a selected trigger name from the list of trigger names results in a display of a corresponding trigger function in a third of the three regions.
Various embodiments of the present invention provide certain advantages and overcome certain drawbacks of the conventional techniques. Not all embodiments of the invention share the same advantages and those that do may not share them under all circumstances. Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the drawings, like reference numerals indicate identical or functionally similar elements. Additionally, the left-most one or two digits of a reference numeral identifies the drawing in which the reference numeral first appears.